Electric lamp



y 1939- w. SOBCZAK El AL. 2,165,987

ELECTRIC LAMP Filed June 29, 1938 2 Sheets-Sheet 1 Fig.2.

Inventors: Walter Sobczak,

Geor Thal,

Their" At't ovhe y.

July 11, 1939. w. SOBCZAK El AL ELECTRIC LAMP Filed June 29, 1958 2 Sheets-Sheet 2 Inventors Walter Sobczak Georg Thai y w aawi Their" Abtor n ey.

Patented July1L193 9 2,165,987

' UNITED STATES PATENT OFFICE- many, assignors to General Electric Company, a corporation of New York Application June 29, 1938, Serial No. 216,590

In Germany July 15, 1937 s 3 Claims. (Cl. 176-32) Our invention relates to electric lamps in genthreaded sleeve or cap in place, in the manner eral and more particularly to lamps which are customary with standard bases, or the base propadapted to project only a narrow beam of light er, without the threaded sleeve or cap thereon, substantially in one direction. Still more particmay be cemented to the lamp bulb and the 5 ularly, our invention relates tov a rotating base threaded sleeve or cap then slid over the base and 5 construction for such lamps whereby the lamp rotatably fastened thereto, preferably by rolling can be rotated in its socket after having been one edge of the .threaded sleeve or cap into an inserted t r v annular groove formed in the cylindrical sleeve In the case of electric lamps which are adapted portion of the underlying base. This interenga to radiate light mainly in one direction, such as ing annular rib and groove thus permits'a ro- 10 those used particularly for signaling, projection, tation of the threaded sleeve or cap with respect reflector and air-raid protection purposes, it is to the lamp base proper but prevents axial disfrequently desirable to change the direction of placement therebetween. light emission by rotating the lamp in its socket. According to a modified form of the invention,

Accordingly, one object of our invention is to prothe sleeve portion of a conventional base provided 15 vide such lamps with a novel rotating base conwith'an Edison screw thread or with protruding struction whereby such a change in the direction bayonet pins, is formed with an annular rib of light emission can be quickly and effectively which fits into a corresponding annular groove made formed in a threadless sleeve which the saidbase Another object of our invention is to provide an encloses and which is cemented to the neck of the 20 electric lamp with a rotating base simple in conlamp bulb. As in the first form of the invention, struction and which will permit rotation of the the rotating base makes it possible, after the lamp lamp in its socket without subjecting the lamp has been screwed into a socket, to rotate the lamp leading-in wires to stresses which might result in at will to e l f r to the right by approximatetheir breakage ly 360. As before, the manufacture and use of 25 Still another object of our invention is to prothis form of base construction is very simple since vide an electric lamp with a rotating base strucit is y necessary o S de the base on the t having stop means for limiting t ti of threadless sleeve, either before or after it has the lamp proper with respect to its rotatable base e ed t0 t e lamp bulb, and to roll the element edge of the base shell into the annular groove 30 According to the invention, the lamp base, in formed in the threadless lamp sleeve. The interone form of the invention, is cemented to the lamp engaging an lar rib and groove thus P mits a bulb neck in the customary manner and is enrotation of the lamp b i respect to the closed by a rotating threaded sleeve or cap which threadless sleeve cemented on the lamp bulb while is locked with said base against axial displace- Preventing axial sp a ment therebetween. 35 ment relative thereto and which is limited in its The rotative lamp base construction is further rotation with respect to said base by suitable provided, according to the invention, with suit-' stop means. The rotating threaded sleeve or able stop means preferably comprising a longithreaded cap makes it possible to rotate the lamp tudinally extending lug on one of the relatively 49 at will to the left or to the right by approximately rotatable portions of the base and a co-operating 40 360 after the lamp has been screwed into a stop pin or projection on the other of the rotatsocket. As a result, the lamp can assume any deable base portions. When the relatively rotatable sired position around its axis without twisting the portions of the base are rotated with respect to lamp leading-in wires and consequently without each other, the 'lug strikes the stop pin, thereby the danger of injury to the said wires. Undelimiting, the rotation of the two parts. 45 sirable rotation of the lamp by vibrations, after Further objects and advantages of our inventhe lamp has been rotated into the desired posl- -tion will appear from the following detailed detio'n, cannot take place because-of the fact that scription of species thereof and from the accomthe base cemented to the lamp bulb neck is subpanying drawings in which:

jected to the pressure of the socket contacts in Fig. 1 is a longitudinal sectional view, partly in 50 the same manner as a' conventional lamp base. elevation, of an electric incandescent lamp. for

The manufacture and use of the rotative base -r Protection P p D dGd with a construction according to the invention is very base comprising our invention; Fig. 2 isa fragsimple. The base can either be cemented to the mentary view, similar to Fig. 1, of a modification lamp bulb in the assembled state, i. e., with the of our invention; Fig. 3 is a longitudinal view,

partly in elevation, of another modification of. our invention; and Fig. 4 is an elevation, partly in section, of a modified form of lamp construe-- tion'according to the invention.

Referring to Fig. 1, the lamp there shown comprises a pear-shaped glass bulb I containing a stem tube 2, a supporting rod or arbor 3 and a;

filament 1 supported by a plurality of support wires 4 extending from said arbor and arrangedin the form of a star. The opposite ends of the filament I are connected to a pair of leading-in or current supply wires 5,6. The bulb I is evacuated through an exhaust tube 8 which, after evacuation of the bulb, is tipped or closed off as shown in the drawings. The lamp bulb-I is pro- ..vided with an opaque coating I over its entire outer surface with the exception of a laterally arranged light outlet window 9 which may be circular or of any other desired shape. If desired,

the opaque coating I0 may be placed on the inner surface of the lamp bulb instead of on the outer surface. The portion of the lamp bulb in which the window 9 is located is made substantially flat, and the window 9 is made somewhat smaller than the flattened bulb portion, as shown, so that the opaque coating III also covers the edge II of said flattened portion of the bulb wall. Because of the opaque bulb coating I0 formed with the window 9 therein, the light of the lamp can be emitted only over a very narrowly limited space' angle.

Attached to the neck I2 of the bulb, preferably by suitable cement, is a base comprising a threadless shell I3, an insulating body I4, and a bottom contact eyelet I5. A threaded sleeve I6 surrounds, and is so mounted on, the base shell I3 as to rotate thereon about the longitudinal axis of said shell while locked against axial displacement relative thereto. For this purpose, the base shell I3 is formed, adjacent that end secured to the insulation I4, with an annular groove I8 into which fits an annular rib or collar I'I formed in the corresponding end of the threaded sleeve I6. The said annular rib I! may be conveniently produced by spinning or rolling the metal of the threaded sleeve I6 into the annular groove I8 in the base shell I3.

To limit the rotational movement between the base proper and the threaded sleeve I6, suitable stop means are provided comprising a lug 29 extending longitudinally from the edge I9 of the threaded sleeve I6 and a co-operating stop pin or projection 2| formed on the free or uncovered edge portion of the base shell I3 and extendingradially outward therefrom. Thus, after a certain amount of rotation of the sleeve I6 relative to the base proper, the stop lug 20 will strike the pin 2| to thereby limit further rotation. The arcuate extent or width of the lug 20 and of the stop pin 2| is made relatively small so as to permit relative rotation between the sleeve I6 and base proper approximating 360. The stop pin 2| conveniently serves as the soldering point for one of the leading-in wires 5, the other leadingin wire 6 being soldered to the bottom contact eyelet I of the 'base.

To insert the lamp in a socket, the base end of the lamp is inserted in the socket in the usual manner and the bulb rotated in the proper direction until the stop pin 2| engages the lug on the threaded sleeve I6. Thereafter, further rotation of the lamp bulb in the same proper direction will also rotate the threaded sleeve I 6 so that it will screw into the threaded portion of the the socket an amountsufllcient to cause engagement of the lamp bottom contact liwith the corresponding socket contact, it' may then be rotated in the opposite direction through an angle approximating 360 to thereby project the narrow beam otilight emitted by the lamp in the desired direction without resulting in outward axial movement of the lamp in its socket and consequent breaking of the contact between the lamp bottom contact I5 and its corresponding socket contact. Since the base proper, i. e., the base shell I3, insulation I 4, and bottom contact I5, is cemented to the bulb, there is therefore no relative rotation therebetween when the lamp is either screwed into or rotated in its socket. Consequently, there is no twisting of the leading-in or current supply wires 5, 6 which might result in breakage of the same.

Referring now to the modification shown in Fig. 2, the lamp there shown difiers from the previous form mainly in the location of the interfitting annular rim and groove I1 and I8 respectively. Thus, in Fig. 2, the annular rim IT in the threaded sleeve I6 and the annular grove I8 in the base shell I3 are formed adjacent the lower or open end of the base, i. e., that end which is cemented to the bulb neck. In addition, the sleeve I6" is extended at its upper end so as'to surround not only the cylindrical portion of the base shell I3 but also the inwardly curved upper portion thereof, the threaded sleeve I6 being correspondingly curved to fit over the said curved portion of the base shell I3. This base construction is of particular advantage where the lamp is to be inserted in a socket of the type in which one of the contacts thereof is adapted to engage the curved or contracted portion of the lamp base shell. With a lamp base of the form shown in Fig. 2, such socket contact will then engage the upper curved or contracted edge of the threaded sleeve or cap I6, and not the curved edge of the threadless shell I3 which lies underneath, as it would with a lamp of the form shown in Fig. 1. As a result, it is considerably easier to rotate the lamp into any desired position in its socket.

If desired, the stop lug 29 may be formed on the upper edge of the threaded sleeve I6 or I8 instead of on the lower edge as shown in the drawings. In such case, the stop pin 2| would also have to be formed on the upper edge of the base shell I3. I

In the modification shown in Fig. 3, a threadless sleeve 22is cemented to the bulb neck I2 and a conventional screw base, comprising a threaded shell 23, an insulatingbody 24, and a bottom contact eyelet 25, rotatably mounted on the said-sleeve 22 by means of the same interfitting annular rib and groove construction disclosed in the preceding forms of the invention. The annular rib I1 is 'formed in the base shell 23 at the lower or open end thereof and, as before, is produced preferably by spinning or rolling the metal of said shell into the annular groove I8 formed in the threadless sleeve '22. Due to this interfitting annular rib and groove construction, the base proper can be rotated around the inner threadless sleeve 22 but is locked against axial displacement relative thereto. As in the preceding forms of the invention, suitable stop means, comprising a. stop lug 29 on the base shell 23 and a co-operating stop pin 2| on the inner'threadless sleeve 22, areprovided to limit rotation between said parts to an angle approximating 360".

In th modification shown in Fig. 4, the lamp there shown differs from that illustrated in Fig.

- 3 only in the particular arrangement of the window 9 and the filament 1 whereby the beam of light emitted by the lamp is projected in a direction approximating that of the longitudinal axis of the lamp, instead of in a direction transversely thereof, as in the preceding forms of the invention. Referring to Fig. 4, the light outlet window 9 is arranged at an inclination to the bulb axis, such as, for instance, forty-five degrees or thereabouts. The filament I is disposed closer to the neck portion of the bulb in such a position that the light emitted by the lamp will form a cone of rays as shown by the dotted lines in the drawings. This cone of rays, when the lamp is rotated in a suitable way, will not strike a wall 2: located behind the lamp since the limiting rays of the cone leave the bulb approximately parallel to the wall.

While we have shown and described the invention as applied to electric incandescent lamps, it

I is obvious that it may be applied equally well to electric discharge lamps and discharge tubes.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. In an electric lamp for projecting a relatively small beam of light, a non-transparent bulb provided with a light-emitting window, a light source within said bulb, a base secured to 30 said bulb and including a shell, a threaded sleeve rotatably mounted on said shell and locked against axial displacement relative thereto, and stop means on said sleeve and said shell for limiting rotation therebetween.

. 2. In an electric lamp for projecting a relatively small beam of light, a non-transparent bulbprovided with a light-emitting Window, a light source within said bulb, an inner sleeve secured to said bulb, a base rotatably mounted on said inner sleeve and locked against axial displacement relative thereto, and stop means on said base and inner sleeve for limiting rotation therebetween.

3. In an electric lamp for projecting a relatively small beam of light, a non-transparent bulb provided with a light-emitting window, a light source within said bulb, and a base attached to said bulb, said base comprising an inner cylindrical member provided with an annular groove, and an outer threaded shell surrounding said inner member and formed with an annular rib extending into said annular groove to thereby permit relative rotation between said outer shell and said inner member while preventing axial displacement therebetween, and stop means on said shell and said inner member for limiting rotation therebetween.

WALTER SOBCZAK. GEORG THAL. 

